#include "stdio.h"

#define PI 3.1415926
#define MAX(a,b) (a)>(b) ? (a) :(b)

//首先定义两个辅助宏
#define   PRINT_MACRO_HELPER(x)   #x 
#define   PRINT_MACRO(x)   #x"="PRINT_MACRO_HELPER(x) 
//编译阶段打印宏内容
#pragma message(PRINT_MACRO(PI))
#pragma message(PRINT_MACRO(PI2))
#pragma message(PRINT_MACRO(MAX(a,b)))
#pragma message(PRINT_MACRO(MAX(x,y)))


void main(void)
{
	printf("exp: show macro during compilation\n");

}
